patch 8.2.1237: changing 'completepopup' after opening popup has no effect

Problem:    Changing 'completepopup' after opening a popup has no effect. (Jay
            Sitter)
Solution:   Close the popup when the options are changed. (closes #6471)
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 37fdc84..71ee94b 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -1951,9 +1951,11 @@
 			{not available when compiled without the |+textprop|
 			or |+quickfix| feature}
 	When 'completeopt' contains "popup" then this option is used for the
-	properties of the info popup when it is created.  You can also use
-	|popup_findinfo()| and then set properties for an existing info popup
-	with |popup_setoptions()|.  See |complete-popup|.
+	properties of the info popup when it is created.  If an info popup
+	window already exists it is closed, so that the option value is
+	applied when it is created again.
+	You can also use |popup_findinfo()| and then set properties for an
+	existing info popup with |popup_setoptions()|.  See |complete-popup|.
 
 
 						*'concealcursor'* *'cocu'*